HIPE
HIPE (Human impacts on ecosystem health and resources of Lake Edward) is Belgian Federal Science Policy Office funded project under BRAIN-Be (2015-2020).
The network is composed of Université de Liège (Alberto Borges), Katholieke Universiteit Leuven (Steven Bouillon), Royal Museum for Central Africa (Jos Snoeks), Institut Congolais pour la Conservation de la Nature (Emmanuel De Merode), and National Fisheries Research Institute (William Okello)
The Virunga National Park (ViNP) is a hot-spot of biodiversity both regionally and globally, and as such, it was designated as a World Heritage Site by the United Nations Educational, Scientific and Cultural Organization (UNESCO), and is recognized for its ecological significance under the UNESCO Man in the Biosphere Programme (MAB). Lake Edward, an integral part of ViNP, is designated as Outstanding Universal Value by the UNESCO. Yet, the ViNP is also designated World Heritage in Danger by the UNESCO, since 1994. As a consequence, the sustainable management and conservation of the biodiversity of the ViNP (including Lake Edward) is of the utmost importance and urgency.
Lake Edward is a large (2325 km²), deep (max depth = 112 m), weakly stratified tropical lake, draining the Virunga volcanoes and the Ruwenzori Mountains. It is presently mesotrophic but was eutrophic a few decades ago. In the 1980’s, the potential annual fish catch of Lake Edward was estimated at 16,000 tons. Lake Edward has not been subject to comparative examination of limnological properties for over 4 decades, despite changes in population growth, land use, fisheries exploitation and regional climate.
Human impacts on ecosystem health and resources of Lake Edward (HIPE) is a multi-disciplinary project bringing together research teams from 3 Belgian Institutions (University of Liège, KULeuven and Royal Museum for Central Africa [RMCA]) and 2 International Institutions (Institut Congolais pour la Conservation de la Nature [DR of the Congo] and the National Fisheries Resources Research Institute [Uganda]). HIPE combines the expertise of researchers in biology, ecology, biogeochemistry, limnology, fisheries and socio-economics.
The main objective of HIPE is to test the causal relationship between the recent environmental changes and the drastic reduction of fisheries productivity using innovative paleo-proxies, coupled to a study of the present lake functioning. Assessing the validity of the various hypotheses, linked to a better understanding of ecosystem function and a thorough estimation of the socio-economic benefits, will help to develop appropriate management actions to mitigate present and future impacts.
Our working hypothesis is that several environmental pressures in the ViNP have disrupted the biogeochemical, structural and functional links between the terrestrial and aquatic ecosystems of the ViNP, leading to a collapse of the main ecosystem service (ES) provided by Lake Edward.
HIPE relies on new in situ sampling but also on the valorization of existing collections hosted e.g. in Belgian Federal Scientific Institutions (RMCA and the Royal Belgian Institute of Natural Sciences [RBINS]), and on a field socio-economic survey allowing to quantify ecosystem goods and services of Lake Edward and its relevance for society, in view of a better conservation by managers and policy makers. HIPE relies on scientific, technical, and methodological expertise developed during past BELSPO initiatives.
HIPE is structured into 5 workpackages (WPs). WP1 will investigate the changes and drivers of change of ecosystem functioning during the recent past (<100 years) based on the analysis of sediment cores, archived bivalve shells and fish specimens using paleo-proxies. These include: carbon (δ13C), nitrogen (δ15N), oxygen (δ18O), stable isotope analysis, Sr:Ca, Mn:Ca, and Ba:Ca ratios, biogenic silicon, carbon:nitrogen and carbon:phosphorus ratios, fossil diatoms, preserved phytoplankton pigments, 210Pb, 137Cs. Recent ecological and biological history of the lake will be analyzed in the light of the following 4 drivers: changes in precipitation, changes in nutrient inputs, changes in phytoplankton assemblage, and changes in sedimentation rates and watershed organic carbon inputs. This should allow to quantify the recent changes in the lake’s productivity and the role of the different drivers, that need to be interpreted in the frame of the present day productivity and overall carbon and nutrient cycling investigated in the frame of WP2.
WP2 is based on new field measurements of standing stocks and ecological processes to describe ecosystem energy and matter flows, and trophic flows through the food web. In particular, we will quantify the transport of organic and inorganic carbon and nutrients from the watershed to the lake, the community composition of benthic and pelagic primary producers and the littoral and pelagic primary production rates. The food web in the lake, and in particular the origin of organic carbon sustaining fish production (terrestrial, littoral, pelagic) will be investigated using carbon (δ13C), nitrogen (δ15N), and hydrogen (δD) stable isotope analyses.
Data from WP2 will be used to understand the biology and ecology of fish studied by WP3 that will also quantify the fish biodiversity and evaluate the impacts of the pressures on their biodiversity. Classical taxonomical identifications of fish species will be assisted with deoxyribonucleic acid (DNA) barcoding, making use of Fish Barcode of Life Initiative (FISH-BOL) database. The food regime of the 6 most economically important fish species (Oreochromis niloticus, Oreochromis leucostictus, Bagrus docmak, Protopterus aethiopicus aethiopicus, Clarias gariepinus and Barbus altianalis) but also of haplochromine cichlid species (that are becoming important in sustaining fish catch due to overfishing on other species) will be determined based on gut content analysis in parallel to the stable isotope analysis. The biology of both tilapia species (O. niloticus and O. leucostictus) will be further investigated. Population structuring of the economically important fish species stocks will be evaluated with microsats.
WP4 will evaluate the ES mainly focusing on fisheries. WP4 will compile recent and historical fish catch data (data rescue) that will be used in addition to data also provided from WP1, WP2 and WP3, as input data to an ecosystem-based fisheries model (Ecopath coupled to Ecosim). This model together with an analysis of socio-economic benefits will allow to develop an ecosystem-based management plan, with operational objectives and reference points, and control measures (input (effort) and output (catch)). The results of the ecosystem-based management plan will be delivered and disseminated among the local stakeholders and policy-makers.
WP5 will ensure the integration and coordination of the different WPs, and will play a major role in the dissemination of the results and knowledge to the end-users. End-users of HIPE are: 1) the general public; 2) the scientific community at large; 3) complementary projects; 4) international initiatives; and 5) local authorities (managers and policy makers).
HIPE is complementary to a series of ongoing BELSPO projects dealing with the biology, ecology, biogeochemistry and geophysics of African catchments and lakes (EAGLES, CHOLTIC, COBAFISH, COBIMFO, BIOSERF and GeoRisca). HIPE will contribute to the mission IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services) and ecoSERVICES, that deal with understanding the link between biodiversity and ecosystem function, goods and services, their effect on sustainable development, human well-being and poverty alleviation.
HIPE addresses the 5 main strategic objectives of the BRAIN-be program (Reinforce the research excellence; Make use of the available scientific and technical capabilities and museum collections; Develop the societal adequacy of our fundamental research; Scientific support to formulate a Belgian position in terms of the threats related to climate and environmental changes; and Promote the Belgian contributions to several international research program). HIPE addresses specifically point 2.1.3 (Assess the effects of Human consumption and production patterns on Sub-Saharan African Ecosystem Health) of the call for proposals 2015 of Axis 1 (Ecosystems, biodiversity, evolution).
Publications from HIPE are available for download from ORBI:
Morana et al. (2020) Methane paradox in tropical lakes? Sedimentary fluxes rather than pelagic production in oxic conditions sustain methanotrophy and emissions to the atmosphere
http://hdl.handle.net/2268/249362
Stoyneva-Gärtner et al. (2020) Diversity and ecology of phytoplankton in Lake Edward (East Africa): Present status and long-term changes
http://hdl.handle.net/2268/246364
